So I got my new to me tank for the 4Runner, mine had a leak on the seam where the suspension hit it at full flex.:o So any way the new tank has everything with it so I can just swap it in place of the old one.;)

I would like to use the old tank in addition to my new one. I do not have the spare tire mounted under the rear of my rig anymore so a great place to put an extra tank. Isaac has moved his tank there already so we know it can be done.

Question is how do I set it up?

Do I leave the fuel pump in and just use a T fitting down the line? If so do I have to use a steel line or can I use rubber fuel line. If I T in near the engine will I mess with my fuel pressure? I don't think so but :confused:

Do I feed the extra tank into the first somehow?

I like the idea of going from tank 1 to tank 2, that way my gauge will show only when I start to empty out from my second tank.

I could add a fuel gauge to my second tank and always know how much I have in either tank.

Could I hook up a switch between the two so I could run of either tank keeping the fuel fresh?

I figure this will add some weight to the rear but my springs are heavy enough that I won't notice it to much, about 150#'s more if full or the weight of 1 1/2 doggies:D

So all you gas guzzlers let me know what is best or best for me at least.:D

PS both tanks are complete, gauge, pump and filler neck.:D

corsair23

12-08-2009, 11:10 PM

I guess you could get all elaborate but my understanding of how the 80 series subtank works is you pump gas from the sub tank into the primary tank once the level in the primary tank is low enough to accept the fuel (i.e. between 1/4 & 1/2 tank left in the primary)...

I'm thinking easy here...You know the capacity of the stock tank...So, once the new tank gets down to a low enough level, click on the pump from an in-cab switch, pump gas from the second tank into the first tank (via the fill tube?), and then shut down the pump. Only concern would be running the pump dry by leaving it on but I'm sure there is a way to come up with a limiter switch that would shut it off...

Dave 2000

12-09-2009, 12:00 AM

I am unsure about your rig, is it petrol (gasoline) with the fuel pump for the injection in the tank? If so then you could fit up both tanks with a pump in each and have a changeover switch which would control the pump/gauge/ and low fuel light if fitted, none of this is too difficult but you would need to return fuel to the tank it is being drawn from. OTOH you have a diesel i.e. no pump in tank you can use a changeover valve supply/return system, you simply switch over to the reserve tank, again the gauge would come with it. The problem with both of the above is you would have to remember if you used up the spare tank ect. An alternative is if the bottom of the reserve tank is slightly higher than the original fitment you could change the fill pipe to go direct into the reserve tank, then fit a pipe from the reserve into the original fitment The gravity would ensure the reserve tank replenished the standard one automatically so no wiring would be needed at all, your original gauge would read full untill the reserve tank run out and the original started to go down, i.e. when your gauge shows empty you really are!!

I prefer that system as the fuel is continually be used and not standing however if you were to damage the main tank (as you already have) then all of your fuel would be gone but with the other system you could run from either.

Just my 2 cents

reagrds

Dave

DaveInDenver

12-09-2009, 06:39 AM

Jeff's method is the way most people do this, the aux tank feeds the main tank using a transfer pump. Downey's tank worked this way. I like the way described by the other Dave but this is more complex. But OTOH you have true redundancy, you know with a spare fuel pump and everything. Personally I would do the simple thing, a tank with a small transfer pump but I'm a cheap, lazy mini truck guy.

RockRunner

12-09-2009, 08:34 AM

I am unsure about your rig, is it petrol (gasoline) with the fuel pump for the injection in the tank? If so then you could fit up both tanks with a pump in each and have a changeover switch which would control the pump/gauge/ and low fuel light if fitted, none of this is too difficult but you would need to return fuel to the tank it is being drawn from. OTOH you have a diesel i.e. no pump in tank you can use a changeover valve supply/return system, you simply switch over to the reserve tank, again the gauge would come with it. The problem with both of the above is you would have to remember if you used up the spare tank ect. An alternative is if the bottom of the reserve tank is slightly higher than the original fitment you could change the fill pipe to go direct into the reserve tank, then fit a pipe from the reserve into the original fitment The gravity would ensure the reserve tank replenished the standard one automatically so no wiring would be needed at all, your original gauge would read full untill the reserve tank run out and the original started to go down, i.e. when your gauge shows empty you really are!!

I prefer that system as the fuel is continually be used and not standing however if you were to damage the main tank (as you already have) then all of your fuel would be gone but with the other system you could run from either.

Just my 2 cents

reagrds

Dave

Spain huh? Cool to see we have gone multi continental welcome aboard. I must have missed your first post.

Anyway I am running gas (petrol) and want to use the gas from the second tank like you suggested so it does not sit and go stale. I need to look under the truck to see how I want to wire this all up but keep the ideas coming. i am sure I will need some help with it anyway:o Not the best at wiring electrical:(

RockRunner

12-09-2009, 08:36 AM

Jeff's method is the way most people do this, the aux tank feeds the main tank using a transfer pump. Downey's tank worked this way. I like the way described by the other Dave but this is more complex. But OTOH you have true redundancy, you know with a spare fuel pump and everything. Personally I would do the simple thing, a tank with a small transfer pump but I'm a cheap, lazy mini truck guy.

Dave,
The second tank is a complete stock set up so I could use the pump that is in there. That was my idea anyway. I want to kep it simple too, incase one breaks we can use the other one.